/*
 * Copyright (C) 2017-2019 Dremio Corporation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.dremio.exec.planner.common;

import org.apache.calcite.plan.RelOptCluster;
import org.apache.calcite.plan.RelTraitSet;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.SingleRel;

/**
 * Create this to handle all metadata queries in a single clause.  Empty, and should not be used to match rules.  Only for metadata convenience.
 */
abstract public class SampleRelBase extends SingleRel {
  /**
   * Creates a <code>SampleRelBase</code>.
   *
   * @param cluster Cluster this relational expression belongs to
   * @param traits  Conventions/Distribution/Collation traits
   * @param input   Input relational expression
   */
  protected SampleRelBase(RelOptCluster cluster, RelTraitSet traits, RelNode input) {
    super(cluster, traits, input);
  }
}
